Composite materials are materials manufactured from two or more constituent materials. Composite parts may be produced by a variety of processes including but not limited to filament winding (FW) and resin transfer molding (RTM).
In conventional FW, a fiber tow—typically wet—is wound around a central mandrel. In developing this process, limitations on the cross-sectional geometries of the manufactured parts has been observed. For example, the need for eventual extraction of the central mandrel without destroying the finished composite part may limit the axial shape of the central mandrel to draftable geometries that are susceptible to movement via drawing and/or pulling. As a result, the shape of the mandrel used for FW is typically limited to relatively simple, convex cross-sections.
In resin transfer molding (RTM), a fiber “layup” (e.g., graphite) is typically added as a sheet or a pre-form into a mold. Resin (heated or otherwise) is then injected into the mold cavity to impregnate the fiber layup, after which the resin is cured to produce the composite part. However, the use of sheets and pre-forms for the layup does not allow for control over fiber orientation. In addition, the use of sheets and pre-forms may restrict the parts to geometries that can be decomposed into relatively planar patches, and may further result in the production of composite parts that require additional and undesirable post-machining (e.g., trimming of excess materials and the like). This post-machining is undesirable inasmuch as it adds cost and complexity to the overall manufacturing process.